pub struct Demo1{
   pub name:String,
   pub age:u32,
   pub birthday:String,
   pub height:u32
}

impl Demo1{
    pub fn new(name: String,
        age: u32,
        birthday: String,
        height: u32)->Demo1{
         Demo1{
            name,
            age,
            birthday,
            height
         }
       
    }
    pub fn addAge(&mut self,age:& u32){
        let  age1=self.age;
        let agenum= add(age1,  age);
        self.age=agenum;
    }
    
}
pub fn add(a:  u32,b: &u32)->u32{
     return a+b;
}
pub struct Demo2{
    name:String,
    age:u32,
    birthday:String,
    height:u32
}
impl Demo2{
    pub fn addName(&mut self,name:&String){
        self.name.push_str(name)
    }
}


